Vehicle hydropneumatic suspension system

Claim 2

A hydropneumatic suspension system for a motor vehicle having a body and wheel supporting means, comprising first and second suspension struts each of which is mounted between said vehicle body and said wheel supporting means and has a chamber filled with pressurized hydraulic fluid, each of said suspension struts being retractable and extensible in response to relative movement between said vehicle body and said wheel supporting means to increase and reduce, respectively, the pressure of the hydraulic fluid in the corresponding chamber, a hydraulic fluid pressure source and a hydraulic fluid reservoir fluidly communicable with said chambers of said suspension struts to supply and discharge hydraulic fluid into and from, respectively, said chambers thereby maintaining the height of said vehicle body substantially constant independently of the load of said vehicle, levelling means disposed between said chambers and said source and between said chambers and said reservoir to control fluid communication therebetween and responsive to increases and reductions of the load of said vehicle to establish said fluid communication between said chambers and said source and between said chambers and said reservoir, an accumulator including a casing having therein first and second hydraulic fluid chambers, a gas chaMber defined therebetween and filled with pressurized gas, and first and second partition members separating said first and second hydraulic fluid chambers, respectively, from said gas chamber, said first and second hydraulic fluid chambers of said accumulator communicating respectively with said chambers of said first and second suspension struts, each of said partition members being responsive to the difference between the fluid pressures in said hydraulic fluid chambers of said accumulator to move toward one of said hydraulic fluid chambers of said accumulator in which one the fluid pressure is lower.

Claim 3

A hydropneumatic suspension system as claimed in claim 1, in which said accumulator further includes two biasing means urging said partition members toward each other.

Claim 4

A hydropneumatic suspension system as claimed in claim 2, in which each of said partition members is a flexible diaphragm member deformably mounted in said casing.

Claim 5

A hydropneumatic suspension system as claimed in claim 2, in which said casing is a cylinder, and in which each of said partition members is a piston slidably mounted in said cylinder.

Claim 6

A hydropneumatic suspension system as claimed in claim 1, in which said gas chamber comprises first and second gas chambers spaced from and communicating with each other and said casing comprises first and second casings spaced from and connected with each other, said first and second casings having therein said first hydraulic fluid chamber, gas chamber and partition member and said second hydraulic fluid chamber, gas chamber and partition member, respectively, said first and second partition members separating said first and second hydraulic fluid chambers from said first and second gas chambers, respectively.

Claim 7

A hydropneumatic suspension system as claimed in claim 5, in which each of said partition members is a flexible diaphragm member deformably mounted in the corresponding casing.

Claim 8

A hydropneumatic suspension system as claimed in claim 1, in which each of said suspension struts includes a cylinder connected to one of said vehicle body and said wheel supporting means, a piston slidably mounted in said cylinder and defining said chamber of said suspension strut therein, and a piston rod connected to said piston and to the other of said vehicle body and said wheel supporting means.

Claim 9

A hydropneumatic suspension system as claimed in claim 1, further comprising first and second hydropneumatic spring means each of which includes a casing and a flexible partition member dividing the interior of said casing into a gas chamber filled with pressurized gas and a hydraulic fluid chamber filled with pressurized hydraulic fluid, said hydraulic fluid chambers of said hydropneumatic spring means communicating respectively with said chambers of said suspension struts.

Claim 10

A hydropneumatic suspension system as claimed in claim 1, in which said level regulating means comprises first and second level regulating devices disposed outside said chambers of said first and second suspension struts, respectively.

Claim 11

A hydropneumatic suspension system according to claim 1, in which said first and second suspension struts cooperate with right and left wheels of the vehicle.

Claim 12

A hydropneumatic suspension system according to claim 1, in which said first and second suspension struts cooperate with front and rear wheels of the vehicle.

Claim 13

A hydropneumatic suspension system for a motor vehicle having a body and wheel supporting means, comprising first, second and third suspension struts acting in two pairs of suspension struts cooperating respectively with right and left wheels and front and rear wheels of said vehicle, each of said suspension struts being mounted between said vehicle body and said wheel supporting means and having a chamber filled with pressurized hydraulic fluid, each of said suspension struts being retractable and extensivle in response to relative movement between said vehicle body and said wheel supporting means to increase and Reduce, respectively, the pressure of the hydraulic fluid in the corresponding chamber, a hydraulic fluid pressure source and a hydraulic fluid reservoir fluidly communicable with said chambers of said suspension struts to supply and discharge hydraulic fluid into and from, respectively, said chambers thereby maintaining the height of said vehicle body substantially constant independently of the load of said vehicle, level regulating means disposed between said chambers and said source and between said chambers and said reservoir to control fluid communication therebetween and responsive to increases and reductions of the load of said vehicle to extablish said fluid communication between said chambers and said source and between said chambers and said reservoir, and first and second accumulators each of which includes a casing having therein first and second hydraulic fluid chambers, a gas chamber defined therebetween and filled with pressurized gas, and first and second partition members separating said first and second hydraulic fluid chambers, respectively, from said gas chamber, said first and second hydraulic fluid chambers of said first accumulator communicating respectively with said chambers of said first and second suspension struts, said first and second hydraulic fluid chambers of said second accumulator communicating respectively with said chambers of said second and third suspension struts, each of said partition members being responsive to the difference between the fluid pressures in said hydraulic fluid chambers of the corresponding accumulator to move toward one of said hydraulic fluid chambers of the corresponding accumulator in which one the fluid pressure is lower.

Claim 14

A hydropneumatic suspension system for a motor vehicle having a body and wheel supporting means, comprising first, second and third suspension struts acting in two pairs of suspension struts cooperating respectively with right and left wheels and front and rear wheels of said vehicle, each of said suspension struts being mounted between said vehicle body and said wheel supporting means and having a chamber filled with pressurized hydraulic fluid, each of said suspension struts being retractable and extensivle in response to relative movement between said vehicle body and said wheel supporting means to increase and Reduce, respectively, the pressure of the hydraulic fluid in the corresponding chamber, a hydraulic fluid pressure source and a hydraulic fluid reservoir fluidly communicable with said chambers of said suspension struts to supply and discharge hydraulic fluid into and from, respectively, said chambers thereby maintaining the height of said vehicle body substantially constant independently of the load of said vehicle, level regulating means disposed between said chambers and said source and between said chambers and said reservoir to control fluid communication therebetween and responsive to increases and reductions of the load of said vehicle to extablish said fluid communication between said chambers and said source and between said chambers and said reservoir, and first and second accumulators each of which includes a casing having therein first and second hydraulic fluid chambers, a gas chamber defined therebetween and filled with pressurized gas, and first and second partition members separating said first and second hydraulic fluid chambers, respectively, from said gas chamber, said first and second hydraulic fluid chambers of said first accumulator communicating respectively with said chambers of said first and second suspension struts, said first and second hydraulic fluid chambers of said second accumulator communicating respectively with said chambers of said second and third suspension struts, each of said partition members being responsive to the difference between the fluid pressures in said hydraulic fluid chambers of the corresponding accumulator to move toward one of said hydraulic fluid chambers of the corresponding accumulator in which one the fluid pressure is lower.

Claim 15

A hydropneumatic suspension system as claimed in claim 12, in which each of said accumulators further includes two biasing means urging said partition members of said accumulator toward each other.

Claim 16

A hydropneumatic suspension system as claimed in claim 13, in which each of said partition members is a flexible diaphragm member deformably mounted in said casing of the corresponding accumulator.

Claim 17

Hydropneumatic suspension system as claimed in claim 13, in which said casing of each of said accumulators is a cylinder, and in which each of said partition members is a piston slidably mounted in said cylinder of the corresponding accumulator.

Claim 18

A hydropneumatic suspension system as claimed in claim 12, in which said gas chamber of each of said accumulators comprises first and second gas chambers spaced from and communicating with each other and said casing of each of said accumulators comprises first and second casings spaced from and connected with each other, said first and second casings having therein said first hydraulic fluid chamber, gas chamber and partition member and said second hydraulic fluid chamber, gas chamber and partition member, respectively, of the corresponding accumulator, said first and second partition members separating said first and second hydraulic fluid chambers from said first and second gas chambers, respectively, of the corresponding accumulator.

Claim 19

A hydropneumatic suspension system as claimed in claim 16, in which each of said partition members is a flexible diaphragm member deformably mounted in the corresponding casing.

Claim 20

A hydropneumatic suspension system as claimed in claim 12, in which each of said suspension struts includes a cylinder connected to one of said vehicle body and said wheel supporting means, a piston slidably mounted in said cylinder and defining said chamber of said suspension strut therein, and a piston rod connected to said piston and to the other of said vehicle body and said wheel supporting means.

Claim 21

A hydropneumatic suspension system as claimed in claim 12, further comprising first, second and third hydropneumatic spring means each of which includes a casing and a flexible partition member dividing the interior of said casing into a gas chamber filled with pressurized gas and a hydraulic fluid chamber filled with pressurIzed hydraulic fluid, said hydraulic fluid chambers of said first, second and third spring means communicating respectively with said chambers of said first, second and third suspension struts.

Claim 22

A hydropneumatic suspension system as claimed in claim 12, in which said level regulating means comprises first, second and third level regulating devices disposed outside said chambers of said first, second and third suspension struts, respectively.